Returning to applications, these include, first of all, topological strings. Here one considers matrix models of a quite general form which are referred to as matrix model networks [1]}, [2]}, [3]}, [4]}, [5]}, [6]}. These matrix model networks have many avatars: on one hand, they may serve as a tool to study (refined) topological strings [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]}, [14]}, [15]}, [16]} and Nekrasov functions [17]}, [18]}, [19]}, on another hand, within the framework of quantum field theory, they describe supersymmetric quiver gauge theories of Seiberg–Witten type, and, at last, at the algebraic level their partition functions are associated [20]}, [21]}, [22]}, [23]}, [24]}, [25]}, [26]}, [27]} with the conformal blocks of Virasoro/W and Ding–Iohara–Miki algebras. Interrelations between these subject is nothing but the AGT correspondence [28]}, [20]}, [21]}, [22]}, [23]}, [24]}, [34]}, [25]}, [26]}, [27]}, [38]}.
